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답안 #535377

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
535377 2022-03-10T06:38:48 Z faik Pipes (BOI13_pipes) C++14
100 / 100
 93 ms 12240 KB 
#include <bits/stdc++.h>

using namespace std;

#define MOD 998244353
#define INF 1000000001
#define LNF 1000000000000000001

#define int ll

typedef long long ll;
typedef pair<int,int> pii;



void solve(){
//#define TEST
	int n,m;cin >> n >> m;
	if(m > n){
		cout << "0";
		return;
	}
	vector<int> netNodeChange(n);
	for(int i = 0;i < n;i++){
		cin >> netNodeChange[i];
	}

	vector<int> edgeWeight(m);
	vector<vector<pii>> edges(n);
	for(int i = 0;i < m;i++){
		int a,b;cin >> a >> b;a--;b--;
		edges[a].emplace_back(b,i);
		edges[b].emplace_back(a,i);
	}
	//find leafs
	queue<int> leafs;
	vector<int> neighbourCount(n);
	vector<int> removedNodes(n);
	for(int i = 0;i < n;i++){
		neighbourCount[i] = edges[i].size();
		if(edges[i].size() == 1){
			leafs.push(i);
		}
	}
	//remove all leafs
	while(!leafs.empty()){	
		int leaf = leafs.front();
		leafs.pop();
		if(removedNodes[leaf])
			continue;
		removedNodes[leaf] = true;
		pii parent;
		for(auto i : edges[leaf]){
			if(!removedNodes[i.first])
				parent = i;
		}
		edgeWeight[parent.second] = netNodeChange[leaf]*2;
		neighbourCount[leaf]--;
		neighbourCount[parent.first]--;
		netNodeChange[parent.first] -= netNodeChange[leaf];
		if(neighbourCount[parent.first] == 1){
			leafs.push(parent.first);
		}
		if(neighbourCount[parent.first] == 0){
			removedNodes[parent.first] = true;
		}
	}
	//find the nodes in the last cycle
	vector<int> cycle;
	for(int i = 0;i < n;i++){
		if(!removedNodes[i])
			cycle.push_back(i);
	}
	//if there is no cycle we are finished
	if(cycle.size() == 0){
		for(int i : edgeWeight)
			cout << i << ' ';
		return;
	} else if(cycle.size()%2 == 0){//even cycle is bad
		cout << '0';
		return;
	}

	int curr = cycle[0];
	int next;int nextWeight;
	for(auto i : edges[curr]){
		if(!removedNodes[i.first]){
			next = i.first;
			nextWeight = i.second;
		}
	}
	edgeWeight[nextWeight] += 2*netNodeChange[cycle[0]];
	netNodeChange[next] -= netNodeChange[cycle[0]];
	netNodeChange[cycle[0]] = 0;
	int last = cycle[0];
	curr = next;

	while(curr != cycle[0]){
		pii next1;
		for(auto i : edges[curr]){
			if(!removedNodes[i.first] && i.first != last){
				next1 = i;
			}	
		}
		edgeWeight[next1.second] += 2*netNodeChange[curr];
		netNodeChange[next1.first] -= netNodeChange[curr];
		netNodeChange[curr] = 0;
		last = curr;
		curr = next1.first;
	}

	if(netNodeChange[cycle[0]] % 2 != 0){
		cout << 0;
		return;
	}

	last = next;
	curr = cycle[0];
	int sign = 1;

	bool firstNode = true;
	while(curr != cycle[0] || firstNode){
		pii next1;
		for(auto i : edges[curr]){
			if(!removedNodes[i.first] && i.first != last){
				next1 = i;
			}	
		}
		edgeWeight[next1.second] += netNodeChange[cycle[0]]*sign;
		last = curr;
		curr = next1.first;
		sign = -sign;
		firstNode = false;
	}
	for(int i : edgeWeight)
		cout << i << ' ';
}

signed main(){
	cin.tie(0);
	ios_base::sync_with_stdio(0);
#ifdef DEBUG
	freopen("i.txt","r",stdin);
	freopen("o.txt","w",stdout);
#endif
	int t = 1;
#ifdef TEST
	cin >> t;
#endif
	while(t--){
		solve();
	}

	return 0;
}

Compilation message

pipes.cpp: In function 'void solve()':
pipes.cpp:92:23: warning: 'nextWeight' may be used uninitialized in this function [-Wmaybe-uninitialized]
   92 |  edgeWeight[nextWeight] += 2*netNodeChange[cycle[0]];
      |                       ^
pipes.cpp:98:13: warning: 'next' may be used uninitialized in this function [-Wmaybe-uninitialized]
   98 |  while(curr != cycle[0]){

Subtask #1
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 91 ms 11700 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 54 ms 9340 KB Output is correct
14 Correct 68 ms 11108 KB Output is correct
15 Correct 72 ms 11716 KB Output is correct
16 Correct 82 ms 9952 KB Output is correct
17 Correct 90 ms 11692 KB Output is correct
18 Correct 60 ms 11680 KB Output is correct
19 Correct 65 ms 11400 KB Output is correct
20 Correct 1 ms 212 KB Output is correct
21 Correct 1 ms 340 KB Output is correct
22 Correct 63 ms 11716 KB Output is correct
23 Correct 51 ms 9320 KB Output is correct
24 Correct 71 ms 11872 KB Output is correct
25 Correct 54 ms 9816 KB Output is correct

Subtask #2
70.0 / 70.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 53 ms 11016 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 0 ms 212 KB Output is correct
13 Correct 0 ms 212 KB Output is correct
14 Correct 0 ms 212 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 0 ms 212 KB Output is correct
19 Correct 0 ms 212 KB Output is correct
20 Correct 0 ms 212 KB Output is correct
21 Correct 0 ms 212 KB Output is correct
22 Correct 1 ms 328 KB Output is correct
23 Correct 59 ms 9860 KB Output is correct
24 Correct 84 ms 12080 KB Output is correct
25 Correct 60 ms 11080 KB Output is correct
26 Correct 0 ms 212 KB Output is correct
27 Correct 0 ms 212 KB Output is correct
28 Correct 1 ms 212 KB Output is correct
29 Correct 1 ms 212 KB Output is correct
30 Correct 70 ms 11612 KB Output is correct
31 Correct 68 ms 12220 KB Output is correct
32 Correct 93 ms 11768 KB Output is correct
33 Correct 78 ms 11720 KB Output is correct
34 Correct 0 ms 212 KB Output is correct
35 Correct 0 ms 212 KB Output is correct
36 Correct 1 ms 212 KB Output is correct
37 Correct 1 ms 212 KB Output is correct
38 Correct 62 ms 11864 KB Output is correct
39 Correct 61 ms 11588 KB Output is correct
40 Correct 73 ms 11988 KB Output is correct
41 Correct 49 ms 12100 KB Output is correct
42 Correct 0 ms 212 KB Output is correct
43 Correct 0 ms 212 KB Output is correct
44 Correct 0 ms 212 KB Output is correct
45 Correct 0 ms 212 KB Output is correct
46 Correct 63 ms 11796 KB Output is correct
47 Correct 74 ms 12028 KB Output is correct
48 Correct 71 ms 12240 KB Output is correct
49 Correct 49 ms 10704 KB Output is correct
50 Correct 0 ms 212 KB Output is correct
51 Correct 0 ms 212 KB Output is correct
52 Correct 0 ms 212 KB Output is correct
53 Correct 0 ms 212 KB Output is correct
54 Correct 69 ms 11756 KB Output is correct